Wafer backside coating process with pulsed UV light source

a backside coating and pulsed uv technology, applied in the direction of semiconductor/solid-state device details, semiconductor devices, solid-state devices, etc., can solve the problems of warping and delamination, and achieve the effect of reducing the risk of warping

Inactive Publication Date: 2014-07-29
HENKEL IP & HOLDING GMBH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The process ensures the semiconductor wafer's backside coating remains intact and functional through the reflow process, minimizing delamination and warpage, as demonstrated by successful bonding and reflow results with the use of a Xenon pulsed UV light source.

Problems solved by technology

However, the thinness of the dies makes them susceptible to warping and delamination in the solder reflow step of the fabrication process.

Method used

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  • Wafer backside coating process with pulsed UV light source
  • Wafer backside coating process with pulsed UV light source
  • Wafer backside coating process with pulsed UV light source

Examples

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example

[0042]An adhesive composition was formulated as follows. A glycidylated o-cresol formaldehyde novolac (30.32 g) (softening point of 85° C., epoxy equivalent weight of 203) was dissolved in tetrahydrofurfuryl acrylate (15.16 g) at 80° C. The solution was cooled to room temperature and the following components were added: trimethylcyclohexyl acrylate (15.16 g); a photoinitiator mixture (2.39 g) consisting of 2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one; 2-phenyl-4-methylimidazole (0.80 g); mercaptan pendant silicone (0.16 g) (molecular weight 4000-7000); and fused silica (16.00 g) (dry sieved at 5 microns). The mixture was hand-mixed the passed four times through a three-roll ceramic mill

[0043]The adhesive composition was spin coated to 40 micron (μm) thickness onto three 100 micron (μm) thick square silicon wafers, 15.24 cm per side. Each wafer was B-staged cured by UV irradiation using a different UV source, with the settings optimized ...

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Abstract

A process for coating a semiconductor wafer with a coating composition comprises curing the coating with a pulsed UV light, thereby preventing delamination during reflow operations. In a particular embodiment, the coating composition comprises both epoxy and acrylate resins. The epoxy resin can be cured thermally; the acrylate resin is cured by UV irradiation.

Description

FIELD OF THE INVENTION[0001]This invention relates to a process for coating the inactive side (backside) of a semiconductor wafer in which the coating is cured using a pulsed UV light source.BACKGROUND OF THE INVENTION[0002]Recent advancements in semiconductor packaging have led to the downsizing of the package through the use of thinner dies in a stacked arrangement (two or more semiconductor dies are mounted on top of one another). This stacking of dies enables increased functionality in a small footprint, allowing for downsizing of the overall semiconductor package. Typically, an adhesive paste or film is used between the two semiconductor dies to ensure package integrity during fabrication operations, such as, wirebonding, molding, and solder reflow, and during end use. However, the thinness of the dies makes them susceptible to warping and delamination in the solder reflow step of the fabrication process. Thus, there is a need for a wafer backside coating that can undergo the r...

Claims

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Application Information

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Patent Type & AuthorityPatents(United States)
IPC IPC(8): H01L21/56
CPCC08L63/00C08G77/28C08L83/08H01L21/56H01L21/6836H01L23/293H01L23/296H01L24/27H01L24/29H01L24/83H01L25/50H01L2224/274H01L2224/27436H01L2224/29H01L2224/29101H01L2224/2919H01L2224/2929H01L2224/29324H01L2224/29339H01L2224/29344H01L2224/29347H01L2224/29355H01L2224/29364H01L2224/29369H01L2224/2937H01L2224/29386H01L2224/29388H01L2224/29393H01L2224/83191H01L2224/83855H01L2224/83856H01L2924/00013H01L2924/01005H01L2924/01006H01L2924/01013H01L2924/0102H01L2924/01029H01L2924/01033H01L2924/0104H01L2924/01046H01L2924/01047H01L2924/01056H01L2924/01057H01L2924/01061H01L2924/01074H01L2924/01077H01L2924/01078H01L2924/01079H01L2924/014H01L2924/0665H01L2924/0635H01L2924/00H01L2924/00014H01L2924/05432H01L2924/05442H01L2924/04642H01L2924/0503H01L2224/29099H01L2224/29199H01L2224/29299H01L23/12
InventorGASA, JEFFREYPHAN, DUNG NGHILEON, JEFFREYHAJELA, SHARADKONG, SHENGQIAN
OwnerHENKEL IP & HOLDING GMBH